Large U.S. multinational companies reported about $4.2 billion in hits to earnings and revenue in the third quarter, driven primarily by swings in the Brazilian real, Japanese yen, Indian rupee and Australian dollar.

A total of 205 companies said currency moves had negatively impacted their results in the third quarter of 2013 – the lowest number since the third quarter the prior year, according to a review of 846 public companies by FiREapps, a foreign exchange risk-management company

U.S. companies reported losing over $4 billion to foreign exchange swings last quarter, and currency volatility could still increase in the third quarter.

Some 233 U.S. companies reported negative foreign currency impacts to their revenue and earnings in the second quarter, according to a quarterly analysis of 800 multinational companies’ conference calls by foreign exchange risk-management company FiREapps. The number of companies reporting those losses was the second-highest since the company started tracking these calls – outpaced only by the second-quarter a year ago when 250 companies cited currency headwinds.

Harley-Davidson Inc.’s revenue, gross margin and profits surged in the first quarter, despite a weather-related drop in motorcycle sales at dealerships, but analysts used its quarterly conference call on Thursday to press Chief Financial Officer John Olin to better disclose how foreign currency movements affect its results.

Glassmaker Corning Inc. was caught off guard by the yen’s recent plunge in value versus the dollar and will spend $100 million over the next two years to insulate itself against additional declines, Chief Financial Officer James Flaws said during an earnings conference call Wednesday.

Dupont’s first-quarter earnings were hampered by a weaker yen and Brazilian real, and those currencies could continue to act as a headwind in the second quarter, Chief Financial Officer Nick Fanandakis said.

“It fell a little faster than anticipated,” Mr. Fanandakis said in an interview, referencing the decline in currency rates.

The plunging Japanese yen plagued International Business Machines Corp.’s first-quarter results, and Chief Financial Officer Mark Loughridge said there’s little in the way of hedging that it can do to offset that, given the nature of its business in the island nation.